Rye bread against prostate cancer

Studies show that a diet containing wholegrain rye can keep prostate cancer at bay. Scientists from Aarhus University will now try to identify the ingredients responsible for this positive health effect.

Rye contains a lot of healthy fibres, minerals and vitamins, but these are not the only virtues of rye. Recent studies show that patients with early-stage prostate cancer benefit from eating a diet containing a high proportion of wholegrain rye.

Scientists from Aarhus University will now try to identify more precisely the substance in rye that is responsible for this beneficial impact on cancer. A better understanding of why rye inhibits the growth of prostate cancer will be a useful step on the way towards producing foods with a documented inhibitory effect.

Special compounds

Within its armoury against potential enemies such as insects, fungi, bacteria and weeds, there is a group of compounds in rye called benzoxazinoids. These compounds increase its resistance to attacks and infections and have an effect on weed growth, but they have also been observed to repress the growth of prostate cancer cells in laboratory experiments. New investigations undertaken by scientists from Aarhus University show that rye grain and bread baked on rye contain considerable quantities of these benzoxazinoid compounds.

Patients with prostate cancer who over a period ate a diet containing a high proportion of rye (about six slices per day) had a decrease in their PSA (prostate-specific antigen) levels – an indicator that the cancer is being suppressed. Laboratory studies have likewise shown inhibition of prostate cancer in transgene mice when the mice ate a diet rich in rye. Other studies have found an inhibitory effect of benzoxazinoids on prostate cancer cells grown in vitro.

- Our hypothesis for the new research project is obvious. Benzoxazinoids in rye products must be one of the main causes of the positive effects of rye on prostate cancer, says the leader of the new project, associate professor Inge S. Fomsgaard from Aarhus University.

Mapping the effect

The scientists will be trying to establish the chemical structure of the benzoxazinoids and their transformation products when they are assimilated by prostate tissue and describe what happens to other molecules in the tissue in the presence of these compounds. This will be done both in the laboratory on prostate and liver tissue from pigs and on patients with prostate cancer.

- We will try to understand which of the compounds have this positive effect on cancer cells in order to optimise the utilisation of the compounds in rye, says Inge S. Fomsgaard.

For many years, scientists have focused on fibre, lignans, polyphenols and alkylresorcinols when searching for the healthy constituents in rye.

- We will include these constituents in our research. When we have identified the active ingredients, we can improve the rye so that it contains the optimum amount of precisely these ingredients. Maybe we will also be able to pave the way for the synthesis of a new lead molecules that can be used for medicinal purposes, says Inge S. Fomsgaard.

The three-year project has received 4.8 million DKK from The Danish Council for Independent Research | Technology and Production Sciences and is an interdisciplinary collaboration between scientists and physicians from Aarhus University (departments of Agroecology, Urology and Pathology) and the Swedish bakery section of the Lantmännen group.